1. Field of the Invention
The present invention relates to a semi-automatic shift implementation control system/method for semi-automatic shifting of a splitter type, preferably a combined splitter and range type, compound transmission. More particularly, the present invention relates to a semi-automatic shift implementation control for shifting a splitter-type compound mechanical transmission wherein all splitter shifting is automatically implemented while all main section shifting is manually implemented. Preferably, if the compound transmission also includes auxiliary range gearing, range shifting is also at least partially automatically implemented.
2. Description of the Prior Art
Compound range-type mechanical transmissions using so-called "double H" type controls wherein a range shift is automatically selected by movement of the shift lever, without requiring the operator to use a button or lever to select a range change, are well known in the prior art as may be seen by reference to U.S. Pat. Nos. 4,561,325 and 4,455,883 and 4,944,197, the disclosures of which are incorporated herein by reference.
Compound mechanical transmissions of the combined splitter and range type are widely used for heavy duty vehicles and very well known in the prior art as may be seen by reference to U.S. Pat. Nos. 4,754,665 and 4,944,197, the disclosures of which are incorporated herein by reference.
Semi-automatic shift implementation systems the compound mechanical transmissions wherein, upon manual shifting into a highest grouping of gear ratios, automatic shifting with that highest grouping only is provided are known in the prior art and disclosed in U.S. Pat. Nos. 4,722,248 and 5,038,627, the disclosures of which are incorporated herein by reference. Semi-automatic shift implementation systems for mechanical transmissions wherein the vehicle operator is required to manually cause a torque interruption and/or achieve synchronous conditions are known in the prior art and are disclosed in U.S. Pat. No. 5,053,961, the disclosure of which is incorporated herein by reference.
These prior art transmission systems were not suited for certain applications as they required a relatively high level of skill and experience to operate, required a significant amount of automation hardware and/or did not permit the operator to shift the transmission in a manner equivalent to shifting a passenger car manual transmission.